PURPOSE: The purpose of this study is to compare the effects of HOE 901 and NPH on glycated hemoglobin and to compare the safety of HOE 901 with NPH in subjects with type I diabetes mellitus. A comparison between the two treatments will also be made in terms of blood glucose variability, hypoglycemia, other indicators of metabolic control, quality-of-life, and pharmacoeconomics. METHODS: This is a phase III, randomized, multicenter, open, NPH human insulin controlled, randomized (1:1), 28-week parallel-group study with two treatment groups (HOE901 and NPH human insulin). A total of 520 patients ( a total for all sites) will be evaluated in this study. The study consists of a 1 to 4-week screening phase and a 28-week treatment phase which includes an initial active dose titration phase. Subjects randomized to the NPH insulin group will continue their previous regimen of injections per day. Subjects randomized to HOE901 will receive a single injection of HOE 901 at bedtime. Both treatment groups will also receive regular insulin in addition to either HOE901 or NPH human insulin. The subjects will be stratified by whether they were being treated with a basal insulin once versus twice daily. This study will involve 5 outpatient visits and 3 inpatient visits. During the screen visit, subjects will undergo a history and physical examination, blood tests, pregnancy screen, dilated eye exam, and fundus photography. Subjects will be instructed in home blood glucose monitoring, issued a glucose meter and supplies, and will be asked to monitor their blood glucose 4x/day. At the following visit, patients who qualify will be admitted to the GCRC for approximately 36 hours, during which 24 hr blood glucose samples will be taken. Patients will also have an EKG and blood tests. Patients are randomized at this visit. Outpatient follow-up visits including blood tests will occur at Weeks 1 & 4. Patients will be readmitted for an inpatient stay, including 24 hr sampling, at Week 8. Outpatient follow-up visits including blood tests will occur at Weeks 12 & 20, with optional eye exam and fundus photos at Week 12. The final admission will occur at Week 28. In addition to 24 hr sampling, an EKG, eye exam, fundus photos, and blood tests will be performed. Patients will restart their prestudy insulin regimen at this visit. RESULTS AND CONCLUSIONS: The study was completed in June 1998. This is a pharmaceutical-sponsored, multicenter study, and results have not been provided to date. SIGNIFICANCE: Type I diabetes mellitus is characterized by general insulin deficiency due islet beta-cell loss and requires insulin replacement therapy. Normal pancreatic beta-cells secrete approximately 50% of insulin as boluses in response to food and the rest as a continuous basal secretion. Longer-acting insulins such as NPH or Ultralente are often used to simulate endogenous basal insulin in the treatment of type I diabetes. However, neither NPH nor Ultralente provides a stable 24 hr basal insulin supply because either the duration of action is too short (NPH) or absorption from the site is erratic (Ultralente). NPH also often results in nocturnal hypoglycemia due to plasma insulin peaks during the night. Consequently, the bedtime NPH dose cannot be safely increased as appropriate, resulting in elevated blood glucose in the morning, a major obstacle to overall euglycemia. The Diabetes Control and Complications Trial has shown that tight blood glucose control greatly reduces the risk of diabetic complications such as retinopathy, neuropathy, and nephropathy. Human insulin analogue HOE901 is a long-acting insulin that, if proven safe and effective, can be given as a single daily injection to provide near normal blood glucose control and a smoother 24 hr basal insulin profile than previously possible with available medications. FUTURE PLANS:The results of this study will provide the basis for future investigation of HOE901.